The present invention relates to an image forming apparatus for outputting a copy image, as in a case of printing images of two original documents on both sides of a single paper sheet with use of an OA (Office Automation) apparatus such as a copying machine.
In this copying machine, an original document is read by through-read, in which a read operation is effected by a stationary-type scanner which scans an original document, fed by an automatic document feeder (ADF), in units of one scan line.
The read image data is subjected to mirror-image conversion and recorded on a page memory. Then, after subjected to a rotational process, where needed, the image data is printed out.
In the prior art, there are directions of images, i.e. portrait/landscape, for each of a vertically positioned original and a horizontally positioned original.
The portrait of the vertically positioned original is defined such that the longitudinal direction of the original coincides with the up-and-down direction of the image. The portrait of the horizontally positioned original is defined such that the longitudinal direction of the original coincides with the up-and-down direction of the image. The landscape of the vertically positioned original is defined such that the transverse direction of the original coincides with the up-and-down direction of the image. The landscape of the horizontally positioned original is defined such that the transverse direction of the original coincides with the up-and-down direction of the image.
As regards the above-mentioned copying machine, where images of two originals are printed on both sides of a single paper sheet, a process is performed with reference to an end face of a first original at which a final main scan is performed and an end face of a second original at which a first main scan is performed.
Consequently, in the case of the portrait of the vertically positioned original and the landscape of the vertically positioned original, the up-and-down direction of an image printed on the observe side coincides with the up-and-down direction of an image printed on the reverse side. However, in the case of the portrait of the horizontally positioned original and the landscape of the horizontally positioned original, the up-and-down direction of an image printed on the observe side is made opposite to the up-and-down direction of an image printed on the reverse side.